USB DACs - Do you get them?

[amey01]

I'm probably one of the most advanced digital streaming people on the forum, but I just don't get the new crop of USB DACs like the Ayre QB-9.

As exemplary as the performance no doubt is, what is the point in having a DAC that accepts only a USB input? Regardless of whether USB does or does not sound better than S/PDIF (most are limited to 16/48), most digital streaming devices out there support S/PDIF primarily and most don't even have USB outputs. Squeezebox, Transporter, Sonos ZPs, Sooloos, Linn DS, Naim HDX, Soundbridge, Olive, the list goes on.

I'm all for a USB input on a normal DAC, but I fail to see why a USB only DAC would be of interest to anyone unless you want a computer in your listening room. And why would you want that? - no nice interface, no remote, noisy hard disk in your room, etc.

So a great DAC like the Ayre becomes dismissed by me. What a shame.

Anyone like to comment or put me in line?

 

[jtwrace]

Yes, I do. I own a Wavelength Crimson.

Here is the explanation: http://www.usbdacs.com/Concept/Concept.html

I use a Mac Mini with SSD and two 2 TB drives. There is no audible noise from the drives. As for a remote I use an itouch. Can't beat it IMO.

 

[Audiophiliac]

I am starting to wonder why all the "stuff" in between my music and my speakers? If I can plug my laptop (Sony TZ150), which is virtually silent, has long battery life, and has an easy to use and manage program for playing my music (foobar....all FLAC files) via a USB cable, into a DAC/Integrated, and have it sound good, I am not sure I need a box that connects my other box to yet another box.

But the SONOS is a pretty cool.

 

[amey01]

I am starting to wonder why all the "stuff" in between my music and my speakers? If I can plug my laptop (Sony TZ150), which is virtually silent, has long battery life, and has an easy to use and manage program for playing my music (foobar....all FLAC files) via a USB cable, into a DAC/Integrated, and have it sound good, I am not sure I need a box that connects my other box to yet another box.

But the SONOS is a pretty cool.

ahh....because you want to control your music without having to get up to a laptop (or have a USB cable dangling from the hi-fi rack to your listening position)?

Granted - jtwrace's solution is one possible.

 

[tonepub]

I'm probably one of the most advanced digital streaming people on the forum, but I just don't get the new crop of USB DACs like the Ayre QB-9.

As exemplary as the performance no doubt is, what is the point in having a DAC that accepts only a USB input? Regardless of whether USB does or does not sound better than S/PDIF (most are limited to 16/48), most digital streaming devices out there support S/PDIF primarily and most don't even have USB outputs. Squeezebox, Transporter, Sonos ZPs, Sooloos, Linn DS, Naim HDX, Soundbridge, Olive, the list goes on.

I'm all for a USB input on a normal DAC, but I fail to see why a USB only DAC would be of interest to anyone unless you want a computer in your listening room. And why would you want that? - no nice interface, no remote, noisy hard disk in your room, etc.

So a great DAC like the Ayre becomes dismissed by me. What a shame.

Anyone like to comment or put me in line?

So what makes you the "most advanced digital streaming person on the forum?"

It's really simple, some want to use a laptop, desktop or Netbook as a source and some don't. Like every other thing out there, the people that have thrown their hat in the ring for USB as the standard think their way is the best.

Audiophilia has always been this way...

 

[Jimna]

So what makes you the "most advanced digital streaming person on the forum?"

It's really simple, some want to use a laptop, desktop or Netbook as a source and some don't. Like every other thing out there, the people that have thrown their hat in the ring for USB as the standard think their way is the best.

Audiophilia has always been this way...

i keep my mouth shut as a owner of a lesser system, but from my point of view truer words have not been spoken. thanks for some validation Jeff, i respect your opinion highly.

 

[amey01]

So what makes you the "most advanced digital streaming person on the forum?"

It's really simple, some want to use a laptop, desktop or Netbook as a source and some don't. Like every other thing out there, the people that have thrown their hat in the ring for USB as the standard think their way is the best.

Audiophilia has always been this way...

Nothing makes me "the most advanced"......because I said "one of", not "the most...." One of, because:

* I was one of the first to take up streaming
* I've put my money where my mouth is and ran a streaming system for a long time
* I have stuck my head out and championed it for a long time
* I have offered more advice on the matter than most others on the forum (Alan possible exception)

So there.

Now - it was just a question. Yes, I understand "different strokes for different folks" - it's just that I see a lot of money being invested (by manufacturers like Ayre) in USB ONLY DACs and I am genuinely interested in what makes this niche tick. Is that too confrontational for you?

I hope not because it wasn't intended in that tone. And Jim - lesser system, better system - I don't care - I'm genuinely interested in your thoughts.

 

[Craig]

ahh....because you want to control your music without having to get up to a laptop (or have a USB cable dangling from the hi-fi rack to your listening position)?

Granted - jtwrace's solution is one possible.

"Get up to a laptop"...??? I often find my laptop sitting on my lap. Or one could simply use a remote. Very convenient.

I agree that a USB input only DAC is very limiting and not the best use of a good DAC. However, maybe the Ayre DAC is specifically designed and optimized just for the USB format and therefore not well suited for other digital inputs.

Music servers seem to be emerging as the main source in many systems. Most people have computers and setting up a quality sounding music server is relatively easy and can be very inexpensive.

The Squeezebox Touch (when it is finally released) will have a USB output.

 

[Rich]

I have to agree with Amey's concern regarding USB-only DACs. Even if I was completely sold on the computer to USB to DAC setup, I would still be concerned about spending a lot of money on a quality DAC that only had one type of output. The way technology changes, more flexibility is always better. When they come out with USB 3.0 or 4.0 and it does something awesomely different for music streaming, is everyone going to buy a new DAC? Or send it back to the manufacturer for updating? Seems like this could be a bit of a merry-go-round every few years.

At the same time, I know that when you find something that just works for you, as JTWrace mentioned above, then you are quite happy to set it up and forget about it. It just works for years and you are happy. So I see both sides of the coin. But if I was buying a DAC, I would definitely want a variety of outputs. I know from experience that my setup often takes me in directions that I didn't anticipate and more than once I have been lucky to have some built-in flexibility of differing types of outputs.

Personally, I have been streaming music since 2000. That's when I bought a Lansonic (now defunct) music server, with a massive (at that time) 160 GB hard drive. Seems kind of puny now. But I have the majority of my music on it, in variable rate mp3, and it works fine for the whole-house music system. But I am ready to have a server-based system for my main system, so now I am in the process of ripping my 2000+ cds onto a NAS RAID in Apple Lossless, which I can then stream all over the house.

I also just purchased a new/used CD player, which has a fantastic DAC that was recently upgraded to have a USB input (among other types of inputs). So I am seriously considering a setup like Jason's long term. Although I am just going to start with an ipod dock and see how I like the sound quality of that. I was blown away at how good some of the rooms at RMAF sounded with songs streaming from the Wadia 170i ipod dock, particularly the Channel Islands Audio room.

 

[Satch]

I'm thinking about the EMU 0404 USB DAC sound card for my desktop computer. Looks like a pretty good deal for $99. YouTube vids> MiniWatt tube amp> AKG 701 headphones. Not my main system, but not bad.

 

[churchill]

I agree with Adam and Rich regarding DAC flexibility. I'd want as many connection options as possible.

 

[Questy]

I have begun to experiment with this type of musical playback this year and decided to set up a computer based FLAC loaded system consisting of a Dell Mini 10V used specifically for music downloads with Foobar. I load all music into a 1TB Fantom Drive outboard Hard Drive. The Mini 10V's USB output is linked to a MAudio Transit to my Cambridge Audio's DAC via a Toslink Cable. The Cambridge has an extremely advanced DAC for its price.

After many hours of playing around with this and tailoring it to my needs, I can say that it sounds amazing. I can't tell the difference with redbook CD playback and love the convenience. I have impressed a few of my friends with this relatively cheap method of USB reproduction and some have pretty expensive loads of gear! If this is the future than I am quite happy with it. HOWEVER, still no where as good as vinyl!

 

[Sambob2]

Although this is not an end all answer to why any manufacturer is making a USB only DAC, I found it interesting. This excerpt is from Ayre's website, it's nothing I could have conjured up, but nonetheless. It is the white paper for the QB-9 DAC, however this section tries to justify why Ayre chooses to make single chassis player/DAC units (they refer to as "One-box") over separates. Why they chose to make a USB only, I don't know.

As far as upgrades or flexibility, I can see that point as mentioned here too. Personally I am not ready to spend the money on a computer based system in addition to all the existing equipment in my system yet. I am currently in the market for a good used CD player and have looked at ARC, Ayre, Esoteric, and Cary. Anyway, this is what I found interesting from the Arye website.

Quoted from Ayre's QB-9 DAC white paper:
"A low-jitter master audio clock is essential for attaining high performance levels of digital audio reproduction. But that low jitter only matters at one critical point—at the D/A chip itself. Jitter-induced timing errors create artifacts that audibly degrade the music signal. Therefore a well-designed one-box disc player places a fixed-frequency master audio clock right next to the D/A chip for the best possible performance.

In contrast, a two-box system splits the system into a disc transport box and a D/A converter box. The two are normally connected with the industry-standard S/PDIF connection which places the master audio clock in the transport box, where it is mixed together with synchronization codes and the audio data and transmitted to the D/A converter box. The D/A converter box must then attempt to recover the critical master audio clock from this jumble of signals for delivery to the D/A chip itself.

The standard solution for a two-box disc player is to use a PLL (Phase-Locked Loop) to control a VCO (Voltage-Controlled Oscillator) in the D/A box, generating the master audio clock. The VCO varies its frequency in order to lock onto the incoming signal sent from the transport box. Unfortunately, a variable-frequency oscillator simply cannot achieve the low-jitter performance of a fixed-frequency crystal oscillator.

Over the years many schemes have been implemented by various manufacturers in attempts to improve the jitter performance of the S/PDIF connection, including dual PLL’s, VCXO’s (Voltage-Controlled Crystal Oscillators), frequency synthesizers, FIFO (First-In, First-Out) buffers for the audio data, external re-clocking (”jitter reduction”) devices, and so forth. While all of these methods are able to reduce the jitter levels, they cannot eliminate the jitter that is inherently added by the S/PDIF connection.

Another approach to reduce jitter that has become increasingly popular in recent years is to use an ASRC (Asynchronous Sample Rate Converter) chip. The idea is that the original audio data is replaced with newly calculated data that represents what the audio data would have been if the incoming signal had most of the jitter filtered out. The technical theory behind this method is sound, as demonstrated by the measured performance, which is generally quite good. However the audible performance of these devices is controversial, and Ayre has avoided this approach as it completely discards the original audio data.

The only correct solution is to place the critical master audio clock in the D/A converter box, next to the D/A chip itself. This has been done in a few products using separate transports and D/A converters, but
there have been drawbacks to these solutions. One scheme added a separate cable that carried the master audio clock signal back upstream to the transport box. While able to achieve low levels of jitter, this new interface was no longer compliant with the S/PDIF standard. Instead a closed system was created that only worked with specific pairs of transport and D/A converter boxes from a single manufacturer.

A well-designed one-box disc player avoids these problems completely. The master audio clock is placed immediately adjacent to the D/A chip, and the rotational speed of the disc is adjusted so that the audio data is read at a rate to match the master audio clock—a simple and elegant solution. Therefore, for a full decade, Ayre only offered one-box disc players."

Sam

 

[tonepub]

Nothing makes me "the most advanced"......because I said "one of", not "the most...." One of, because:

* I was one of the first to take up streaming
* I've put my money where my mouth is and ran a streaming system for a long time
* I have stuck my head out and championed it for a long time
* I have offered more advice on the matter than most others on the forum (Alan possible exception)

So there.

Now - it was just a question. Yes, I understand "different strokes for different folks" - it's just that I see a lot of money being invested (by manufacturers like Ayre) in USB ONLY DACs and I am genuinely interested in what makes this niche tick. Is that too confrontational for you?

I hope not because it wasn't intended in that tone. And Jim - lesser system, better system - I don't care - I'm genuinely interested in your thoughts.

Just always have to ask the question, it's the editor in me...

On many levels I also think that offering a USB only product is a serious limitation for the reasons mentioned. Charlie Hansen of Ayre is a very opinionated man and feels he is ALWAYS right.

They said at CES that they could have offered SPDIF and optical as well, but it would have increased the price to implement properly. Perhaps in the future, they will release a DAC with all the input formats covered.

 

[sleepysurf]

As lossless streaming becomes more mainstream (pardon the pun), we'll no doubt see even more manufacturers each lauding their specific approach as being the "best". We now have DAC's offering S/PDIF, TOSlink, USB, firewire, and AES input options, and I think I've even read something about I2S being the next great thing. Each of these technologies require a high level of engineering expertise for optimal implementation, so it's unlikely that a DAC offering multiple input options can excel at all of them. Unless all the manufacturers agree upon a single standard (quite unlikely), we'll have to pick and choose from competing designs, based on our individual needs, biases, and real world listening tests. With cheaper and higher capacity SSD's coming down the pike, we might end up having to "re-think" the whole server/storage paradigm anyways. Rather than knocking one DAC's approach vs. another, I say we should all be thankful to have so many choices, and hopeful that the burgeoning growth in this sector will ultimately prove to be the savior of high-end audio.

 

[Audioseduction]

As lossless streaming becomes more mainstream (pardon the pun), we'll no doubt see even more manufacturers each lauding their specific approach as being the "best". We now have DAC's offering S/PDIF, TOSlink, USB, firewire, and AES input options, and I think I've even read something about I2S being the next great thing. Each of these technologies require a high level of engineering expertise for optimal implementation, so it's unlikely that a DAC offering multiple input options can excel at all of them. Unless all the manufacturers agree upon a single standard (quite unlikely), we'll have to pick and choose from competing designs, based on our individual needs, biases, and real world listening tests. With cheaper and higher capacity SSD's coming down the pike, we might end up having to "re-think" the whole server/storage paradigm anyways. Rather than knocking one DAC's approach vs. another, I say we should all be thankful to have so many choices, and hopeful that the burgeoning growth in this sector will ultimately prove to be the savior of high-end audio.

Well said Alan!

 

[sleepysurf]

BTW, according to Engadget, the Squeezebox Touch has apparently been delayed yet again, now until Feb... http://www.engadget.com/2009/12/10/squeezebox-touch-delayed-until-february-bah-humbug/

Bummer

 

[Craig]

Speaking of the Squeezebox Touch. It apparently has a USB port but that is only an INPUT for photos and reading music but is NOT AN OUTPUT device!

That means this music server product with a USB port is not going to be compatible with any of the USB only DACs including the Ayre model.

Another shortcoming I find with the Touch is that the touchscreen is on the device but not on the remote. You'd think a major remote control company would include a touchscreen remote with it. I guess their business plan is to encourage consumers buy an additional touchscreen remote for an extra $250. But then what do you do with the basic remote that came with the Touch?

These companies are shooting themselves in the foot.

 

[JonFo]

To my mind, the ideal ‘one-box’ solution is a DLNA-enabled playback device that integrates the network based file retrieval, the DAC and the pre-amp all in one single box.

This implies that a well designed unit can achieve near-perfect digital audio reproduction, as the PCM data stream is unpacked from the network stream, it can be clock-synched to the same clock as the DAC’s. And by having the pre-amp integrated as well, very low-noise on the analog side can be achieved in that path. And if it’s an advanced pre-amp, then room-correction, sub crossovers and other goodies can be layered on in the digital domain with full clock-synch as well.

One controls a unit like this from an iPodTouch/iPhone or from a laptop using a DLNA control point. Very slick.

Oh, and this already exists in several incarnations. Go check out Linn’s lineup. It’s extremely cool.

My favorite product in this category is the uber-Denon, their ground-breaking AVP-A1HD preamp. I love mine, as it renders ripped CD’s better than any transport I’ve ever heard.

 

[sleepysurf]

Re the Touch possibly outputting to a USB DAC, there IS a 3rd party developer/modder already looking into that... http://forums.slimdevices.com/showthread.php?t=70407

As for a handheld touchscreen controller, I think Logitech realizes they can't compete with an iTouch or iPhone running the iPeng app, which is probably a better interface than their own Duet Controller. Personally, I'm hoping the iPeng developer will release a Palm WebOS version, so I can use it with my Pre.